Oxygen Transfer Agent Conditioning for OCM Selectivity
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Solution Overview
Problem
Current oxidative coupling of methane (OCM) and oxidative dehydrogenation (ODH) processes for producing ethylene and propylene face challenges in achieving high yields, selectivities, and catalyst durability due to thermodynamic limitations and high energy consumption, while also emitting significant greenhouse gases and NOx.
Innovation Solution
Conditioning of oxygen transfer agents (OTAs) and catalysts with sulfur-containing compounds, increasing particle density through reducing agents, and removing non-selective redox oxygen (NSRO) to enhance reaction rates, selectivities, and attrition resistance, thereby improving the efficiency and longevity of OCM and ODH reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional high temperature steam cracking is used to produce olefins, then production capacity is achieved, but energy consumption is high and greenhouse gas emissions are significant
Solution Approach 1:
The patent changes the fundamental reaction parameters by using oxidative dehydrogenation at lower temperatures (500-800°C) instead of conventional steam cracking at high temperatures (800-900°C). This parameter change reduces energy consumption while maintaining olefin production capacity, directly resolving the contradiction between productivity and energy loss.
2Object-generated harmful factors
If oxidative dehydrogenation is implemented to reduce emissions, then greenhouse gas and NOx emissions are lowered, but reaction selectivity and yield are insufficient
Solution Approach 1:
The patent introduces an oxygen transfer agent as an intermediary substance that mediates the oxidation process. The OTA selectively transfers oxygen to the hydrocarbon feedstock, enabling controlled oxidative dehydrogenation that achieves both low emissions and high selectivity to desired olefin products, resolving the contradiction between environmental benefits and manufacturing precision.
Solution Approach 2:
The patent optimizes reaction parameters including temperature (500-800°C), oxygen partial pressure, and contact time to achieve maximum selectivity and yield in oxidative dehydrogenation. These parameter changes enable the process to simultaneously reduce emissions and improve manufacturing precision by controlling the oxidation pathway.
3Productivity
If oxygen transfer agent is used to improve reaction efficiency, then selectivity and yield increase, but catalyst attrition and operating lifetime are reduced
Solution Approach 1:
The patent employs composite oxygen transfer agents combining metal oxides (such as Mn, Fe, Cu, or Co oxides) with support materials like alumina or silica. This composite structure enhances both the catalytic activity for high selectivity/yield and the mechanical strength for attrition resistance, resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent creates oxygen transfer agents with non-uniform oxygen distribution, where lattice oxygen provides selective oxidation for high yield while surface oxygen species are controlled to minimize unwanted reactions. This local quality differentiation maintains high productivity while improving catalyst stability and lifetime.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The described methods significantly increase the selectivity, yield, and operational lifetime of OTAs and catalysts, reducing greenhouse gas emissions and NOx production, while maintaining high conversion rates and selectivity to desired olefin products.
Implementation Method 1
The ODH of ethane is a selective catalytic process that produces primarily ethylene and water as products and is an exothermic reaction
Implementation Method 2
treating the oxygen transfer agent or the catalyst with a sulfur-containing compound at a site or at a time that is different from where or when the saturated hydrocarbon is converted
Implementation Method 3
Increasing the particle density of the oxygen transfer agent or catalyst by exposing (or treating or contacting) the oxygen transfer agent or the catalyst with a reducing agent
Data Source
AI summary
Improvements in the commercial viability of oxygen transfer agents (OTAs) and/or catalysts associated with the OCM and the ODH of hydrocarbons to olefins through enhancement of one or more of the selectivity, yield, rate and lifetime of the OTA and/or catalyst is described by one or more of (i) exposing the OTA or the catalyst to a sulfur-containing compound at a site or at a time that is different from where and when the saturated hydrocarbon is converted by the OTA or the catalyst to an unsaturated hydrocarbon; (ii) increasing the particle density of the OTA or the catalyst by treating the OTA or the catalyst with a reducing agent at a site different from where the saturated hydrocarbon is converted by the OTA or by the catalyst to an unsaturated hydrocarbon; and (iii) removing non-selective redox oxygen (NSRO) present on the OTA by subjecting the OTA to a gas that is substantially free of any molecular oxygen.